I have been struggling with this issue for the last few days and after all this juggling I have figured out that all I need is the current Index from the datasource method to up
if you implement ModelController (as in Apple example), use it's method indexOfViewController
- (void)pageViewController:(UIPageViewController *)pageViewController didFinishAnimating:(BOOL)finished previousViewControllers:(NSArray *)previousViewControllers transitionCompleted:(BOOL)completed {
myDataViewController *currentView = [pageViewController.viewControllers objectAtIndex:0];
NSInteger currentIndex = [_modelController indexOfViewController:currentView];
[self displayPageNumber:currentIndex];
}